From 51eaa0d56aadeea9eb3a3c011189d20bf9333bc7 Mon Sep 17 00:00:00 2001 From: Wesley Wiser Date: Sun, 19 Jan 2025 13:04:28 -0600 Subject: [PATCH 1/2] Clean up uses of the unstable `dwarf_version` option - Consolidate calculation of the effective value. - Check the target `DebuginfoKind` instead of using `is_like_msvc`. --- .../src/debuginfo/metadata.rs | 3 +- .../rustc_codegen_llvm/src/debuginfo/mod.rs | 49 ++++++++++--------- compiler/rustc_session/src/options.rs | 1 + compiler/rustc_session/src/session.rs | 8 ++- 4 files changed, 34 insertions(+), 27 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs index 8d782a618fc07..2a1a12f3ce592 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs @@ -919,8 +919,7 @@ pub(crate) fn build_compile_unit_di_node<'ll, 'tcx>( .unwrap_or_default(); let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo); - let dwarf_version = - tcx.sess.opts.unstable_opts.dwarf_version.unwrap_or(tcx.sess.target.default_dwarf_version); + let dwarf_version = tcx.sess.dwarf_version(); let is_dwarf_kind = matches!(tcx.sess.target.debuginfo_kind, DebuginfoKind::Dwarf | DebuginfoKind::DwarfDsym); // Don't emit `.debug_pubnames` and `.debug_pubtypes` on DWARFv4 or lower. diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs index e6778411365fb..5089560784a0d 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs @@ -22,6 +22,7 @@ use rustc_session::config::{self, DebugInfo}; use rustc_span::{ BytePos, Pos, SourceFile, SourceFileAndLine, SourceFileHash, Span, StableSourceFileId, Symbol, }; +use rustc_target::spec::DebuginfoKind; use smallvec::SmallVec; use tracing::debug; @@ -93,29 +94,31 @@ impl<'ll, 'tcx> CodegenUnitDebugContext<'ll, 'tcx> { pub(crate) fn finalize(&self, sess: &Session) { unsafe { llvm::LLVMRustDIBuilderFinalize(self.builder) }; - if !sess.target.is_like_msvc { - // Debuginfo generation in LLVM by default uses a higher - // version of dwarf than macOS currently understands. We can - // instruct LLVM to emit an older version of dwarf, however, - // for macOS to understand. For more info see #11352 - // This can be overridden using --llvm-opts -dwarf-version,N. - // Android has the same issue (#22398) - let dwarf_version = - sess.opts.unstable_opts.dwarf_version.unwrap_or(sess.target.default_dwarf_version); - llvm::add_module_flag_u32( - self.llmod, - llvm::ModuleFlagMergeBehavior::Warning, - "Dwarf Version", - dwarf_version, - ); - } else { - // Indicate that we want CodeView debug information on MSVC - llvm::add_module_flag_u32( - self.llmod, - llvm::ModuleFlagMergeBehavior::Warning, - "CodeView", - 1, - ); + + match sess.target.debuginfo_kind { + DebuginfoKind::Dwarf | DebuginfoKind::DwarfDsym => { + // Debuginfo generation in LLVM by default uses a higher + // version of dwarf than macOS currently understands. We can + // instruct LLVM to emit an older version of dwarf, however, + // for macOS to understand. For more info see #11352 + // This can be overridden using --llvm-opts -dwarf-version,N. + // Android has the same issue (#22398) + llvm::add_module_flag_u32( + self.llmod, + llvm::ModuleFlagMergeBehavior::Warning, + "Dwarf Version", + sess.dwarf_version(), + ); + } + DebuginfoKind::Pdb => { + // Indicate that we want CodeView debug information + llvm::add_module_flag_u32( + self.llmod, + llvm::ModuleFlagMergeBehavior::Warning, + "CodeView", + 1, + ); + } } // Prevent bitcode readers from deleting the debug info. diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index 4ce6382512978..c7af40a8ad4ea 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -1803,6 +1803,7 @@ options! { "output statistics about monomorphization collection"), dump_mono_stats_format: DumpMonoStatsFormat = (DumpMonoStatsFormat::Markdown, parse_dump_mono_stats, [UNTRACKED], "the format to use for -Z dump-mono-stats (`markdown` (default) or `json`)"), + #[rustc_lint_opt_deny_field_access("use `Session::dwarf_version` instead of this field")] dwarf_version: Option = (None, parse_opt_number, [TRACKED], "version of DWARF debug information to emit (default: 2 or 4, depending on platform)"), dylib_lto: bool = (false, parse_bool, [UNTRACKED], diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs index 1f03de3f53db8..c0f5f0d4a9e9e 100644 --- a/compiler/rustc_session/src/session.rs +++ b/compiler/rustc_session/src/session.rs @@ -732,6 +732,11 @@ impl Session { self.opts.cg.split_debuginfo.unwrap_or(self.target.split_debuginfo) } + /// Returns the DWARF version passed on the CLI or the default for the target. + pub fn dwarf_version(&self) -> u32 { + self.opts.unstable_opts.dwarf_version.unwrap_or(self.target.default_dwarf_version) + } + pub fn stack_protector(&self) -> StackProtector { if self.target.options.supports_stack_protector { self.opts.unstable_opts.stack_protector @@ -1263,8 +1268,7 @@ fn validate_commandline_args_with_session_available(sess: &Session) { } if sess.opts.unstable_opts.embed_source { - let dwarf_version = - sess.opts.unstable_opts.dwarf_version.unwrap_or(sess.target.default_dwarf_version); + let dwarf_version = sess.dwarf_version(); if dwarf_version < 5 { sess.dcx().emit_warn(errors::EmbedSourceInsufficientDwarfVersion { dwarf_version }); From 4d5a63f8825e127040a078d3a81d7904a7cfb1ad Mon Sep 17 00:00:00 2001 From: Wesley Wiser Date: Sun, 19 Jan 2025 13:22:25 -0600 Subject: [PATCH 2/2] Add tracking issue to docs --- src/doc/unstable-book/src/compiler-flags/dwarf-version.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/doc/unstable-book/src/compiler-flags/dwarf-version.md b/src/doc/unstable-book/src/compiler-flags/dwarf-version.md index c5e86f17df741..e88799d2cf044 100644 --- a/src/doc/unstable-book/src/compiler-flags/dwarf-version.md +++ b/src/doc/unstable-book/src/compiler-flags/dwarf-version.md @@ -1,5 +1,9 @@ ## `dwarf-version` +The tracking issue for this feature is: + +---------------------------- + This option controls the version of DWARF that the compiler emits, on platforms that use DWARF to encode debug information. It takes one of the following values: